Network nodes

ABSTRACT

The invention relates to a process for transmission of data via a communication network to a terminal, and a network node for performance of the process. The data are transmitted to the terminal via the network node which can be connected with two or more terminals. On the network side at the network node for the transmission of data, a data stream is received which consists of useful data and protocol data. The network node removes the majority of the protocol data from the data stream received on the network side at the network node for the transmission of data and switches the remaining data stream in the direction of the terminal.

[0001] The invention is bases on a priority application DE 10149001.1which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] The invention relates to a process for transmission of data via acommunication network to a terminal, and a network node which has afirst interface to connect the network node with two or more terminalsand with a second interface to connect the network node with acommunication network.

[0003] The invention is based on the connection, common today, ofcomputers and servers in a computer network.

[0004] The computer and server are connected together and with one ormore routers by a multiple access medium. These components connectedwith the multiple access medium communicate with each other via anEthernet or fast Ethernet protocol. The components are physicallyconnected with the multiple access medium as follows: the computers andserver of a spatial area are each connected with a floor switchallocated to this spatial area which is in turn connected with the otherfloor switches. The floor switch as such does not process the incomingdata streams. It merely constitutes a coupling which ensures a galvanicconnection between the components connected to it and allows easyuser-friendly installation of the communication network.

[0005] The invention is now based on the object of improving theperformance of a communication network.

SUMMARY OF THE INVENTION

[0006] This object is achieved by a process for transmission of data viaa communication network to a terminal where in the process the data aretransmitted to the terminal via a network node which can be connectedwith two or more terminals, and where on the network side on the networknode or the transmission of data a data stream is received whichconsists of useful data and protocol data, wherein the network noderemoves the majority of the protocol data from the data stream receivedon the network side by the network node for transmission of data, andswitches the remaining data stream in the direction of the terminal.Network node with a first interface for connecting the network node withtwo or more terminals and with a second interface for connecting thenetwork node with a communication network, wherein the network node hasa control unit which is designed so that it removes the majority of theprotocol data from a data stream received on the network side via thesecond interface, which data stream consists of useful data and protocoldata and is directed towards one of the terminals connected with thefirst interface, and switches the remaining data stream in the directionof this terminal.

[0007] The basic concept of the invention lies in the moving of protocolprocessing functions from the terminals into a network node locatedbefore the terminals.

[0008] This firstly gives the advantage that the network cards for theterminals need be equipped considerably more simply and reduces the loadon the terminals from communication tasks. This saves costs on theterminal side. It is also advantageous that the scope of the data to beexchanged between the terminals and the network node is less than thescope of the data to be exchanged between the floor switch and theterminals. Accordingly the transmission complexity can be reduced in thenetwork cards and in the line installations.

[0009] Further advantages arise from the centralisation in the field ofnetwork management and fault elimination.

[0010] Advantageous embodiments of the invention are described in thesub-claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention will now be described in more detail as an examplewith reference to several embodiment examples and the enclosed drawings.

[0012]FIG. 1 shows a block circuit diagram of a communication systemwith two network nodes according to the invention.

[0013]FIG. 2 shows a functional view of a network node according to FIG.1.

[0014]FIG. 1 shows a communication system with several terminals TE1 toTE6, with a communication network KN, with a router ROUT and with twonetwork nodes FSW1 and FSW2.

[0015] The terminals TE1 to TE6 are computers or servers. Terminals TE1to TE6 can however also be other terminals such as multimedia terminals,printers or copiers.

[0016] Of the network nodes and routers connected to the communicationnetwork KN, FIG. 1 shows as an example the network nodes FSW1 and FSW2and the router ROUT. It is also possible for terminals to be connectednot only via the network nodes KN but also directly via thecommunication network KN.

[0017] The communication network KN is a communication network by meansof which data can be exchanged between the components connected to thecommunication network. Preferably the communication network KN is a bussystem. It is however also possible that the communication network KNcomprises active components such as switching nodes, gateways, routers,bridges. It is also possible here that the communication network KNconsists of several different part networks which use differentcommunication protocols for data exchange or are allocated to differentnetwork operators. Such part networks can also be radio networks.

[0018] The router ROUT is a router which connects the communicationnetwork KN with one or several further communication networks. Therouter ROUT could also be omitted.

[0019] The network nodes FSW1 and FSW2 are connected on the network sidewith the communication network KN and on the terminal side with theterminals TE1 to TE3 or TE4 to TE6. The number of terminals connectedwith the network nodes FSW1 and FSW2 is selected as an example.

[0020] The network nodes FSW1 and FSW2 can each be connected with two ormore terminals. For transmission of data via the communication networkKN to one of the terminals TE1 to TE3, the data are transmitted via thenetwork node FSW1, and for transmission of data to one of the terminalsTE4 to TE6, the data are transmitted via the network node FSW2 to therelevant target terminal. Here the data are guided by the communicationnetwork KN1 to the network node FSW1 or FSW2, or the network nodes FSW1or FSW2 take from the communication network KN the data addressed to oneof the terminals TE1 to TE3 or TE4 to TE5.

[0021] On the network side, on the network nodes FSW1 and FSW2 ontransmission of data a data stream is received which consists of usefuldata and protocol data.

[0022] The network nodes FS1 and FS2 now remove the majority of theprotocol data from the data streams received on the network side at thenetwork node for transmission of data, and pass the remaining datastreams in the direction of the terminal to which the relevant datastream is addressed. Thus the protocol overhead on the terminal sidefrom the network nodes FS1 and FS2 is reduced in relation to the networkside protocol overhead.

[0023] The detailed function of the network nodes FSW1 and FSW2 isexplained as an example below using the network node FSW1:

[0024]FIG. 2 shows the network node FSW1 which on the terminal side isconnected to the terminals TE1 to TE3 and on the network side to thecommunication network KN.

[0025] The network node FSW1 has two interfaces INT1 and INT2 and acontrol unit CONTR.

[0026] The interface INT1 serves to connect the network node FSW1 withtwo or more terminals. It consists for example of a plug strip via whicha multiplicity of connecting cables can be connected with the networknode FSW1. The interface INT2 serves to connect the network node (FSW1)with the communication network KN.

[0027] The control unit CONTR has a computer with peripheral componentsand a software platform sitting on this computer, which for exampleconsists of an operating system and a database system. The control unitCONTR also has several application programs. When these applicationprograms are run on the hardware and software platform of the controlunit CONTR, the control unit CONTR performs the functions PHTE1 toPHTE3, SW and PHN described below.

[0028] The function PHN controls the network-side communication of thenetwork node FSW1. It removes the majority of protocol data from a datastream, received on the network side via the interface INT2, whichconsists of useful data and protocol data and is directed towards one ofthe terminals connected to the interface INT1.

[0029] It is particularly advantageous here that the function PHN forthe terminals connected with the network node FSW1 processes thecommunication protocols of one or more communication layers and removesthe protocol data allocated to these communication layers.

[0030] Special advantages arise from removal of the protocol data of thefirst (simple point-to-point protocol) and/or the third layer (e.g.saving IP addresses). The removal of the protocol data of the fifth andhigher layers brings scarcely any more savings.

[0031] Overall good results are achieved if the network nodes processthe communication protocols of layers 1 to 4 for the terminals connectedto them.

[0032] The function PHN comprises, in the embodiment example accordingto FIG. 2, several processes of which FIG. 2 shows the processes P1 toP3. The processes P1 to P3 are allocated to the terminals TE1, TE2 orTE3. The function PHN also comprises sub-functions which firstly controlthe “lifecycle” of the processes, i.e. generate and terminate theprocesses. For each terminal connected to the network node FSW1, thefunction PHN generates a process allocated to this terminal. Thefunction PHN also comprises sub-functions which allocate the data streamincoming at the interface INT2 to one of the processes P1 to P3. Forthis the function PHN determines to which of the terminals TE1 to TE3the data stream is directed. This is given for example by a targetaddress in the data stream. It then transfers the processing of the datastream to the process allocated to this terminal.

[0033] Processes P1 to P3 each comprise protocol processing units forthe protocol levels which are processed by the PHN function for theterminal concerned. FIG. 2 shows for example four protocol processingunits PL1 to PL4 which process the communication protocols of layers 1,2, 3 and 4. It is naturally also possible for the processes P1 to P3 toprocess the protocols of more or fewer layers. The layers are hereoriented in relation to their task content to the OSI layer model(OSI=open system interconnection). Protocol families not specified byOSI must be classified accordingly.

[0034] For example the network node FSW1 communicates on the networkside via a multiple access protocol. The protocol processing units PL1and PL2 then process the protocol data of MAC protocols (MAC=mediumaccess control) such as an Ethernet protocol, the DQDB protocol or aToken protocol.

[0035] The protocol processing units PL3 and PL4 then for exampleprocess the IP protocol (IP=internet protocol) or the TCP/UDP protocol(transmission control protocol, user datagram protocol).

[0036] Here it is also advantageous that one IP address is allocated tothe network node FSW1 for all terminals connected to this and hence onlyone IP address is required for all terminals connected with the networknode FSW1.

[0037] The protocol data allocated to the communication protocolsprocessed by processors P1 to P3 are then removed from the data streamconcerned by the PHN function so that only the data stream reduced bythe protocol data allocated to these communication protocols istransmitted to the function SW for switching as the residual datastream.

[0038] The function SW switches the residual data stream then towardsthe terminal. Here it has access to the data determined by the PHNfunction on the target address of the data stream and passes theremaining data stream to the one of the functions PHTE1 to PHTE3 whichis allocated to the target terminal.

[0039] The functions PHTE1 to PHTE3 control the terminal-sidecommunication of the network node FSW1 with the terminals TE1, TE2 orTE3. They transmit to their allocated terminal the remaining data streamwhich the function SW has transmitted in the direction of this terminal.

[0040] Here it is advantageous that the protocol stack of thecommunication between the functions PHTE1 to PHTE3 and terminals TE1 toTE3 is as simple as possible. This ensures that the protocol overhead tobe added for communication between the functions PHTE1 to PHTE3 and theterminals TE1 to TE3 is kept as small as possible.

[0041] In particular it is advantageous that the network node FSW1, onthe network-side reception of the data stream, sends a data stream toone of the terminals TE1 to TE3 which consists of the useful data of thereceived data stream and protocol data, the scope of which is reduced bymore than half in comparison with the scope of protocol data of thereceived data stream. This means that the reduction of protocol data bythe function PHN and the addition of protocol data by the functionsPHTE1 to PHTE3 complement each other so that in total the scope of theprotocol data is reduced by more than 50%.

[0042] The functions PHTE1 to PHTE3 in the embodiment example each havea protocol processing unit PL1′ which processes a protocol of the firstcommunication level.

[0043] Preferably this protocol is a simple point-to-point protocol. Theresidual data streams are thus transmitted to the relevant terminal bymeans of a point-to-point protocol.

1. Process for transmission of data via a communication network to aterminal where in the process the data are transmitted to the terminalvia a network node which can be connected with two or more terminals,and where on the network side on the network node or the transmission ofdata a data stream is received which consists of useful data andprotocol data, wherein the network node removes the majority of theprotocol data from the data stream received on the network side by thenetwork node for transmission of data, and switches the remaining datastream in the direction of the terminal.
 2. Process according to claim1, wherein the network node processes the communication protocols oflayers 1 to 4 for the terminals connected to it.
 3. Process according toclaim 1, wherein the network node on the network side communicates via amultiple access protocol and that the network node on the terminal sidecommunicates via a point-to-point protocol.
 4. Process according toclaim 1, wherein the network node (FSW1), on the network-side receptionof the data stream, sends to the terminal a data stream which consistsof the useful data of the received data stream and protocol data, thescope of which is reduced by more than half in comparison with the scopeof protocol data of the received data stream.
 5. Network node with afirst interface for connecting the network node with two or moreterminals and with a second interface for connecting the network nodewith a communication network, wherein the network node has a controlunit which is designed so that it removes the majority of the protocoldata from a data stream received on the network side via the secondinterface, which data stream consists of useful data and protocol dataand is directed towards one of the terminals connected with the firstinterface, and switches the remaining data stream in the direction ofthis terminal.
 6. Network node according to claim 5, wherein the controldevice is also designed so that it processes the communication protocolsof layers 1 to 4 for the terminals connected with the network node andswitches the data stream reduced by the protocol data allocated to thiscommunication protocol, as a remaining data stream, to the terminalconcerned.
 7. Network node according to claim 5, wherein the controldevice is also designed so that it transmits the remaining data streamto this terminal by means of a point-to-point protocol.